Machine for cleaning solid articles



Aug. 7, 1951 J. BJORKSTEN 2,563,151

MACHINE FOR CLEANING SOLID ARTICLES Filed July 24, 1944 2 Sheets-Sheet l v IN V EN TOR.

Aug. 7, 1951 J. BJORKSTEN MACHINE FOR CLEANING sous ARTICLES 2 Sheets-Sheet 2 Filed July 24, 1944 JNVENTOR.

Fatenteci Aug. 7, 195i UNITED STATES PATENT OFFICE MACHINE FOR CLEANING SOLIDARTICLES Johan Bjorksten, Chicago, 111. Application 'July24, 1944, Serial No. 546,288 3 Claims. (Cl. 134-411) This invention relates'to machines for cleaning articles, and specifically to machines effecting such cleaning in wholeor in part by means of foam.

l-leretofore, cleaning has been eifected by exposure to condensing vapors, by impingement of liquids, by exposure to turbulent liquids, and in other like manners. The drawback of such methodsof'prior art hasbeen that where the cleaning liquid was thrown against the article to be cleaned, with the intensity necessary for best results, the resultant agitation would cause excessive foam unless the detergent compositionpresent wasreduced in quantity to-much less than'the optimum amount. In the devices of prior art, if a high detergent content and extreme intensity of impingement were used at the same time, foam would be generated in such abundance that it would overflow from the machine, and objectionablyfill the surrounding space. Therefore, cleaning machines of prior art have been compromises, In

order to avoid excess foam, they have sacrificed either the optimum concentration of the detergent or the optimum conditions of impingement of the cleaning liquid on the articles to be cleaned, or both.

The present invention has-for an object cleaning machines where optimum rates ofimpingement and optimum detergent concentrations can be used simultaneously, without causing an overflow of foam.

Another object is a cleaning machine of improved efiiciency.

Another object is a cleaning machine where continuous separationof dirt is efiected by means of froth flotation.

Another object is an improved dishwashing machine.

Further objects will become apparent as the following detailed description proceeds.

- Figure 1 is a cross-sectional view in the vertical plane of one embodiment of the invention. Figure'2 is a corresponding horizontal cutaway-plan view of the same embodiment. Figures 3 and 4 are vertical cross-sectional views-of other embodiments, Figure 3 being in perspective.

The extreme left part of the device shown in Figs. 1 and 2 contains a-means I for generating foam. This means maybe a revolving paddle wheel, partly immersed in a strong solution of a detergent. When the wheel is brought to revolve by a motor or any other suitable power means (not shown) it will beat air (or any other gas if desired) into the detergent solution, thereby generating foam. The level of the detergent may be maintained constant by automatic means (not shown) such as a super-positioned reservoir the air intake of which is at the desired liquid level, or by a float controlled valve, orin any other of thenumerous manners well known or obvious to any skilled engineer. Clearly, air or a gas may also besuppliedif desired, by a suitable intake or a meter (not shown) The foam generated passes through a wide opening 25 into the intermediate part of the device,.,inwhichare placed the articles to becleaned. The rising foam surrounds these, loosening and carrying with'it dirt or impurities present. 7

"Iihis intermediate part may or may not contain fixturesorholders'l toreceive the objects to be cleaned, dependent on the nature and form of these'objects.

.3 is a cover, upon removal of which the articles to be. cleaned may be conveniently positioned in the: machine.

Having. passed through the intermediate :section of the machine, the foam, and the dirt carried withit, enter the extremeright portion of the machine, which'contains a foam breaker 5. Thisfoam breakermaybe of the type in common usage for breakingioam in chemical reactionkettles, namely, a rake -like rod revolving horizontally soqas to beat continually the .ascendingfoam, thereby breaking the foam bubbles. The means used tolcause the foam breaking arms 5 tozrevolve withthe shaft H) are not-a part'of this invention, and are not shown. Usually, an electric motor :is preferred for this purpose. The particular'form or shape of this foam breaker is irrelevant; similar :results :are obtained by the use of detached thinrods protruding radially from the shaft [0, like 'thespokes in a bicycle wheel; and, in fact, any solid member moved intermittently through the foam-would havesuch a breaking effect tea more or less pronounced degree. Instead of using a mechanical beating action'I may achieve the foam breaking eifcct by the installation in this partof themachine of a vibrator 21%, as shown in Fig; '3, adapted to impart vibrations to a member 34 contacting the foam, or of a generator of localized' ultrasonic waves, orin any other'manner known to the :art. 2 and 21a represent-an opening, through which air, or'a gas contained inthe foam'may escape, if such a gas was added at -l to aid the formation of foam.

While diiferent specific means have'been described by way of example and not of limitation, it is apparent that the invention is not resting upon any of these specific means, but relates to the broad idea .of generatin foam in one part 3 of the apparatus, exposing the articles to be cleaned to such foam, and breaking it in another part of the apparatus.

As an improvement which is desirable, though not absolutely indispensable, Fig. 1 shows a filter plate 6 for separation of the dirt carried by the foam, and a duct 4 through which the detergent liquid resulting from the broken foam, flows back to the foam generating part of the machine. The dirt accumulated on 6 may be removed when desired through the normally covered aperture 31.

Fig. 4 is a vertical longitudinal section through another embodiment of the invention, which is designed for cleaning of a continuous flow of articles. This process is particularly adapted for the rapid cleaning of objects of round or fairly regular shape.

Foam is generated by passing a gaseous medium such as air through a sieve plate 36 which hereplays the same part as the whipping wheel I in Figs. 1 and 2 and through a strong detergent solution 29. The gaseous medium is introduced through a tube or pipe 28. The foam passes through the cleaning column 3| to the moving foam breaker 5b, where it is broken. The gaseous component of the foam escapes at 211) while the liquid component is returned to 29 via a filter 6b and a duct 41).

The articles to be cleaned 23 enter the cleaning column through a hopper l6 and a sprung flap 19 which prevents the foam from entering the hopper [6. These articles then move through the cleaning column 3|, for example by gravity, counter-currently to the cleaning foam and in contact therewith. They leave the cleaning column at the sprung flap I8, which is actuated by the gravity of the articles, and when not so actuated, prevents loss of the foam. The cleaned articles fall into the receiving means II which may be a flushing tank, a gravity chute, a con veyor, a wire screen tray, or any like means for further storing or processing the said articles.

The invention thus is manifestly of a broad nature and is not to be limited in any manner except by the claims in which it is intended to cover all novelty inherent in the invention as broadly as possible, in view of prior art.

Having thus disclosed my invention, I claim:'

1. In a cleaning machine, the combination of an agitating means acting on a detergent solution to thereby produce foam, a housing to convey said foam, separate from the solution from which it was produced, away from the device and into contact with articles to be cleaned, a housing to contain such articles to be cleaned, a means of access to this housing for the purpose of introducing and removing such articles, a housing to convey said foam away from such articles after said foam has been passed over them and to convey said foam to a foam breaker device, said foam breaker device being a means for reducing said foam to liquid solution, said device consisting of a part rotatable at a high rate of speed with respect to the speed of said stream of foam entering the device, said part being sufllciently large to intercept substantially the full breadth of the stream of said foam upon rotation of said part, and a means to convey the liquid produced by the foam breaking device to the foam producing device.

2. In a cleaning machine, the combination of an agitating means acting on a detergent solution to thereby produce foam, a housing to convey said foam, separate from the solution from which it was produced, away from the device and into contact with articles to be cleaned, a housing to contain such articles to be cleaned, a means of access to this housing for the purpose of introducing and removing such articles, a housing to convey said foam away from such articles, after said foam has passed over them, and to convey said foam to a foam breaker device, said foam breaker device being a means for reducing said foam to liquid solution, said device consisting of a part translatorily movable at a high rate of speed with respect to the speed of said stream of foam entering the device, said part being sufficiently large to intercept substantially the full breadth of the stream ofsaid foam upon translatory motion of said part, and a means to return the liquid produced by the foam breaking device to the foam producing device.

3. In a cleaning machine, the combination of an agitating means acting on a detergent solution to thereby produce foam, a housing to convey said foam, separate from the solution from which it was produced, away from the device and into contact with articles to be cleaned, a housing to contain such article to be cleaned, a means of access to this housing for the purpose of introducing and removing such articles, a housing to convey said foam away from such articles, after said foam has passed over them, and to convey said foam to a foam breaker device, said foam breaker device being a means for reducing said foam to liquid solution, said device consisting of a part movable at a high rate of speed with respect to the speed of said stream of foam entering the device, said part being sufficiently large to intercept substantially the full breadth of the stream of said foam, upon such motion of said part, and a means to return the liquid produced by the foam breaking device to the foam producing device.

JOHAN BJORKSTEN.

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